Why an InfoObj. value shows up when running query but it's not in the ODS?

We've got an ODS which has PO records, multiple PO records could contain the same contract number. When we run a query based on this PO ODS, expend the list for the contract number field (0Contract), find a value listed, but it's not in this ODS.

We wonder how this value was from.

We check the defination of this InfoObject 0Contract, under Business Explorer tab, the Display field is "Key", the "Query Def. Filter Value Selection" field setting is "Only Values in InfoProvider", and the "Query Execution Filter Val. Selectn" field setting is "Only Posted Values for Navigation", sth wrong with these settings?